Unit 12: Ecology

EcologyGuided Notes

Part 1 – Principles of Ecology(LT #1-#3)

What is Ecology? _____________________ – the study of the interactions among living things, and

between living things and their surroundings. Ecologists study ________________________ at different levels of organization. Ecologists research methods include observation, ______________________________,

and modeling.

Levels of Organization _______________________ – an individual living thing (ex: alligator) _______________________ – a group of the same species that lives in one area (ex:

alligators in a swamp) _______________________ – a group of different species that live together in one

area (ex: alligator, turtles, fish, algae, bacteria, and plants that live in the swamp)

_______________________ – includes all the organisms as well as the climate, soil, water, rocks, and other nonliving things in a given area.

__________________ – a group of ecosystems that have the same climate and similar dominant communities.

______________________ – the parts of Earth where life exists.o ____________ –the collection of all living things that live in the biosphere.

Biotic and Abiotic Factors Biotic Factors – ___________________ things in an ecosystem Abiotic Factors – __________________________ things in an ecosystem Together biotic and abiotic factors determine the _______________ and

______________________ of organisms, populations, and communities within ecosystems.

Unit 12: Ecology

Habitat and Niche _______________ – all of the biotic and abiotic factors in the area where an

organism lives. ______________ – composed of all the physical, chemical, and biological facts that

a species needs to survive, stay healthy, and reproduce. You can think of a habitat as _____________ a species lives and a niche as ________

it lives within its habitat.

Latitude and Climate Climate – the long-term pattern of ________________ conditions in a region. It

includes facts such as average temperature, precipitation, and humidity. Broad pattern of climate tends to be cold and dry toward the ____________ and

hot and wet toward the __________________. Earth has _______ main climate zones (based on average temperature and

precipitation):o ____________ Climate Zone – far northern and southern reaches of the

planeto ____________________ Climate Zone – surrounds the equator, runs from

the tropic of Cancer to the tropic of Capricorno ____________________ Climate Zone – located in the broad area between

the polar and tropical climate zones

Abiotic Factors of Climate Sunlight

o The __________________ heating of Earth by the Sun, caused by the Earth’s _____________, results in the 3 climate zones

Air and Water Movement:o Uneven heating of the Earth creates movement in the air and water.

Warmer air _________, cooler air _________. This, along with the _________________ of the Earth, causes weather patterns and thus climate.

Landmasses:

Unit 12: Ecology

o Landmasses break-up the heating or air and water. Land absorbs heat much ____________ than air and water. Both of which can shape climates. _______________________ can also play major factors in climates.

Rain Shadows

Biomes The Earth has 6 major biomes characterizes by temperature and average

precipitation: Tropical

o Tropical rain forest Grassland

o Tropical grasslando Temperate grassland

Desert Temperate

o Temperate deciduous foresto Temperate rain forest

Taiga Tundra

Ocean Ecosystems _________________ Zones – the ocean can be divided into zones in several ways. Simplest:

o ______________ Zone – open oceano ______________ Zone – ocean floor

Light:o Photic Zone – portion of the ocean that receives plentiful ______________o Aphotic Zone – depths of the ocean where _______________ doesn’t reach

Distance From the Shoreline and Water Depth:o __________________ Zone – the strip of land between the high and low tide

lineso ________________ Zone – extend from the intertidal zone out to the edge

of the continental shelf

Unit 12: Ecology

o ________________ (Oceanic) Zone – extend from the edge of the neritic zone to the base of the continental shelf

o _______________ Zone – lies below 2,000 meters and is in complete darkness

Oceanic Habitats Coral Reefs – found within _________________ climate zones where water

temperatures are warm year-round. Kelp Forests – found in _________, nutrient-rich waters.

Estuaries ________________ – a partially enclosed body of water formed where a river

flows into an ocean. Estuaries are _______________ productive ecosystems, on a level comparable to

tropical rain forests and coral reefs.

Freshwater Ecosystems Freshwater ecosystems include _____________ (stream and rivers) and

___________________ water (lakes, ponds, and wetlands).

Streams and Rivers Streams from wherever ______________________ exceeds ___________________ and

excess water drains from the surface of the land. Streams grow with distance and join together to form _______________. _____________________ – a region of land that drains into a river, a river system,

or another body of water.

Lakes and Ponds ____________________ Zone – located between the high and low water makes

along the shoreline ___________________ Zone – open water located farther out from the shore ___________________ Zone – lake or pond bottom

Biogeochemical Cycles Biogeochemical Cycles – the movement of a particular ______________ through

the biological and geological, or living and nonliving parts of an ecosystem. _________________ is a major player in completing these cycles, typically by

decomposing chemicals or by making chemicals available to other organisms. Biogeochemical cycles include:

o The _____________ cycleo The _____________ cycleo The ________________ cycleo The _______________________ cycle

The Water Cycle _______________________ – the process by which water changes from liquid to gas.

Unit 12: Ecology

_________________________ – the process where water enters the atmosphere by evaporating from the leaves of plants.

________________________ – water, in either solid or liquid form, that falls back to the earth’s surface.

The Carbon Cycle 4 main processes move carbon through the carbon cycle:

o Biological Process – ____________________, respiration, and decompositiono Geochemical Processes – _______________ and volcanic activityo Biogeochemical Processes – decomposition of dead organisms that

stores carbon in ______________ fuelso Human Activities – mining, burning of forests and _____________ fuels

The Nitrogen Cycle All organisms require ________________ to make amino acids, which are used to

build _______________. Nitrogen makes up 78% of Earth’s __________________________ Nitrogenous compounds are found in the ____________ produced by many

organisms and in dead and decaying ___________________ matter. Nitrogen also exists in the ocean and large bodies of ________________. Nitrogen is a major component in _____________ fertilizer. Nitrogen ______________________ – the process by which bacteria convert

nitrogen gas (N2) into ammonia (NH3)o Very important process because it makes ________________ available to

the rest of an ecosystem, since other organisms have no way of utilizing nitrogen gas.

____________________________ – the process where bacteria convert nitrates into nitrogen gas to be released back into the atmosphere.

The Phosphorus Cycle Phosphorus is essential to living organisms because it is a component of

______________________ acids, which make up DNA and RNA. Phosphorus does not enter the _________________________, but remains mostly on

land in rock and soil minerals and ocean sediments.

Part 2 – Energy in Ecosystems(LT #4-#5)

Producers Without a constant source of _____________, living systems cannot function.

o ____________________ is the main energy source for life on Earth. Producers – organisms that get their energy from _________________ resources Producers provide ______________ for other organisms in an ecosystem. Producers are ____________________, or organisms that make their own food.

Unit 12: Ecology

There are 2 types of producers, those that capture energy from _______________, and those that use ___________________ energy.

_____________________________ – process where autotrophs use light energy to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates, such as glucose.

o Ex: ______________, algae (protists), cyanobacteria ___________________________ – the process where organisms use chemical energy

to produce carbohydrates.o Ex: ___________________ in deep sea vents, soil bacteria

Consumers ________________________ – organisms that get their energy by eating other living

or once-living resources, such as plants or animals. _______________________ – organisms that rely on other organisms for their

energy and food supply.o ___________________ – plant eaterso ___________________ – eat animals/meato ___________________ – eat both plants and animalso ___________________ – feed on plant and animal remains or dead matter,

known as detrituso ___________________ – break down organic matter

Feeding Relationshipso Energy flows through an ecosystem in ________ direction, from the _________ or

inorganic compounds, to _______________________ (producers), and then to ______________________ (consumers).

o Food Chain – a series of steps in which organisms transfer _____________ by eating and being eaten.

Food Webs and Trophic Levels ________________ __________ – links all the food chains in an ecosystem together. Trophic Levels – each _____________ in a food chain or food web.

o (Primary) Producers – make up the ____________ trophic levelo Consumers – make up the _____________, etc. Each consumer depends

on the trophic level below it for _______________.

Ecological Pyramids Ecological Pyramid – diagram that shows the relative amounts of ____________

or ____________ contained within each trophic level in a food chain or food web.

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o Energy Pyramidso Biomass Pyramidso Pyramids of Numbers

Energy Pyramids Only about __________ of the energy available within one trophic level is

transferred to organisms in the next trophic level.

Biomass Pyramid Biomass – The total amount of living _____________ within a given trophic level

o Typically expressed as _____________ of organic matter per unit area.o The biomass pyramid represents the amount of potential ____________

available for each trophic level in an ecosystem.

Pyramid of Numbers Based on the number of _____________________ organisms at each trophic level.

o For some ecosystems, the shape of the pyramid of numbers is the _____________ as that of the energy and biomass pyramids.

Part 3 – Interactions in Ecosystems(LT #6-#9)

Community Interactions Competition – organisms of the same or different species attempt to use an

ecological resource in the same ____________ at the same _____________. Predation – an interaction in which one organism _____________ on another

organism. Symbiosis – any relationship in which two species live closely ________________.

o Mutualism – both species _________________ from the relationship.o Commensalism – one member of the association benefits and the

other is neither ________________ or __________________.o Parasitism – one organism lives ______ or _______________ another

organism (host) and harms it.

Unit 12: Ecology

Competitive Exclusion Principle Competitive Exclusion Principle – when two species are competing for the

same ___________, one species will be better suited to the niche, and the other species will be ________________ into another niche or become _______________.

Ecological Equivalents Ecological Equivalents – species that occupy ______________ niches but live in

different _________________________ regions.

Characteristics of Populations Geographic Distribution – the area ______________________ by a population.

o Population Dispersion – the way in which individuals of a population are _________________ in an area or volume

Population Density – the number of _________________________ per unit area.

Population Growth 3 factors affect population _____________:

o Number of ______________o Number of ______________o Number of individuals that _____________ or ____________ a population

_____________________ – the movements of individuals into an area. (Increases population)

_____________________ – the movements of individuals out of an area. (Decreases population)

Exponential Growth Occurs when the individuals in a population reproduce at a ______________ rate. Under ideal conditions with ______________________ resources, a population will

grow _________________________. Produces a ______-shaped curve.

Logistic Growth As resources become ___________ available, the growth of a population slows or

________________. Logistic growth __________________ a period of exponential growth. Produces an _____-shaped curve. Carrying Capacity – the __________________ number of individuals in a

population that the environment can normally and consistently support

Unit 12: Ecology

Limiting Factors Limiting Factors – a factor that causes population growth to decrease.

o Density-Dependent Factors – limiting factors that affected by the number of individuals in a given area.

Ex: competition, predation, parasitism, diseaseo Density-Independent Factors – aspects of the environment that

limit a population’s growth regardless of the density of the population.

Unusual weather, natural disasters, seasonal cycles, and human activities

Ecological Succession Succession – the sequence of ___________ changes that regenerate a damaged

community or create a community in a previously uninhabited area.o _________________ Succession – the establishment and development of

an ecosystem in an area that was previously uninhabited. Pioneer Species – the ____________ organisms that that live in a

previously _______________________ area.o __________________ Succession – the reestablishment of a damaged

ecosystem in an area where the soil was left intact.

Part 4 – Environmental Issues(LT #10)

Age Structure Diagramso Age Structure Diagrams – shows the population of a country broken down

by _______________ and ________ group.

Human Population Growtho The size of the human population tends to ___________________ with time.o _________________________ – the scientific study of human populations.o The growing human population exerts pressure on Earth’s ________ resources.

o _____________________ Resources – resources that are used faster than they form.

Ex: ___________ fuels (oil, coal, natural gas)o ____________________ Resources – resources that cannot be used up or

can replenish themselves over time.

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Ex: _________, solar, ___________ (hydroelectric)

Human Activities Human activities have greatly affected the _________________________.

o Hunting and Gathering – early hunters and gatherers caused a mass _____________________ of animals.

o Agriculture – humans began growing crops and raising livestock and horses. This provided humans with a ___________________ supply of food.

____________________ – large fields that are planted with a single crop year after year.

The _____________ Revolution – agricultural advances that greatly ___________________ the world’s food supply.

o Industrial Growth and Urban Development – these processes ________________ air, water, and soil. Dense human communities produce ___________ that must be disposed of. Suburban growth consumes farmland and places stress on ____________________ and natural __________________.

Ecological ____________________ – the amount of land necessary to produce and maintain enough food and water, shelter, energy and waste.

Air Quality ___________________ – any undesirable factor, or pollutant, that is added to the

air, water, or soil. ______________ – a type of air pollution caused by the interaction of sunlight

with pollutants produced by fossil fuel emissions.o Made of particulate matter and ground-level _____________ (O3)o Particulates – microscopic bits of ___________, metal, and unburned

fuels that are produced by many different industrial processes ___________ Rain – rain produced when pollutants in the water cycle cause the

________ of rain to drop below normal levels.o Caused by the burning of _____________ fuels, especially ____________.

The Greenhouse Effect The Greenhouse Effect – occurs when ______________ dioxide, water, and

methane molecules absorb energy ____________________ by Earth’s surface and ___________ the release of this energy from Earth’s atmosphere.

Unit 12: Ecology

_______________ Warming – the trend of increasing global temperatures that is believed to be cause by increased emissions of carbon dioxide into the atmosphere.

Ozone Layer Ozone Layer – layer of ________________________ with a high concentration of

ozone gas (O3).o Absorbs ___________________ UV radiation before it reaches Eartho Gases called CFC’s (chlorofluorocarbons) ______________ the ozone layer.

Water Quality Pollution can also have a major impact on ______________ ecosystems. ___________________ contaminants, raw sewage, trash, and other waste products

are only a few pollutants that make their way into rivers, lakes, and streams. Runoff from farms and cities may contain ________________ chemicals and debris

that can disrupt the chemical _________________ of freshwater ecosystems.o For example, detergents and ____________________ used in fields can affect

lake ecosystems by stimulating plant and algae overgrowth.

Biomagnification Biomagnification – a _______________ moves up the food chain as predators eat

prey, accumulating in _______________ concentrations in the bodies of predators. Unlike energy in a food chain, toxic materials ___________ as it moves up

trophic levels.

Biodiversity Biodiversity – the sum total of the genetically based variety of all organisms

in the ____________________.o Ecosystem diversityo Species diversityo Genetic diversity

Threats to Biodiversity

Unit 12: Ecology

Loss/Altering of Habitato Habitat ________________________ – occurs when a barrier forms that

prevents an organisms from accessing its entire habitat. Hunting Species to Extinction

o Economic reasons (__________________) Introducing Toxic Compounds Into Food Webs

o ___________________ and Biomagnification Introducing Foreign Species to New Environments

o _____________________ Species – any organism that was brought to an ecosystem as the result of human actions. They typically have an aversive affect on native species.

What can be done? When Rachel ________________ book Silent Spring was published in 1962, the

wheels were set in motion for the creation of the modern environmental movement. The book, which described how the pesticide __________ was affecting wildlife, brought about public uproar and helped lead to a ___________ on the use of DDT in the United States. Since then, a variety of measures have been put into place, both to restore Earth’s biosphere and to __________________ it from degradation.

We refer to this movement as __________________________.

Conservation Conservation – the wise management of ___________________ resources.

o _________________________ development – a practice in which natural resources are used and managed in a way that meets current needs without hurting _________________ generations.

_______________________ Species Act – works to protect individual species from extinction

o _____________________ Species – species whose being protected under the Endangered Species Act leads to the preservation of its habitat and all of the _______________ organisms in its community.

o Called an umbrella species because its protection means a ___________ range of other species will also be protected.